Separator



Aug. 4, 1959 M M; NON 2,897,972

SEPARATOR Filed March 28, 1956 United States Patent O Machine Company, South Walpole, Mass., a corporation of Massachusetts Application March 28, 1956, Serial No. 574,504,

3 Claims, (Cl. 210-512) This invention relates to apparatus for separating solid particles from liquid suspensions and pertain-s more V specifically to apparatus for separating particles of dirt or other foreign matter from'aqueous suspensions or dispersions of pulp fibers.

It has hitherto been proposed to employ apparatus of the so-called centrifugal or cyclone type for the purification of wood pulp dispersions. In order to achieve adequate separation, it has been necessary to provide a very small outlet for the particles of dirt or other foreign material which are separated from the pulp suspension within the chamber of the apparatus, the diameter of this outlet normally being only about twice as large as the length of the pulp fibers themselves. Inasmuch as the particles of foreign material frequently are even larger than the pulp fibers, there has been a tendency for this outlet to become plugged by accumulated particles, tlfus rendering the device inoperative.

, One object of the present invention is to provide apparatus for separating solid particles from liquid suspensions having a novel construction facilitating the clearing of obstructions from the outlet for the solid particles.

A second object is to provide apparatus of the type described in which the wall of the chamber at the outlet for the solid particles is radially elastically expansible to permit distortion of the outlet and facilitate removal of obstructions from it.

Still another object is' to provide apparatus of the type described in which the wall of the chamber at the outlet for the solid particles comprises an elastic rubberlike material to permit radial enlargement of the outlet when the internal pressure is greater than normal operating pressure, thus permitting ready cxpulsion of any accumulated solid particles within the outlet which tend to obstruct it. I

Other and further objects will be apparent from the drawings and from the description which follows.

In the drawings:

Fig. 1 is a view in side elevation, partly broken away and in section, showing one embodiment of the invention;

Fig. 2 is a view in section taken along line 2-2 of Fig. 1 and Fig. 3 is a view in vertical section on an enlarged scale, showing the lower portion of the'device shown in Fig. l.

As will be seen from the drawings, the apparatus comprises an elongated chamber 8 having a generally circular cross-sectional configuration provided at one end with a conical portion 10 terminating in end wall 16 at the other or base end of the chamber. An outlet 18 is located adjacent the base end of the chamber and is provided with valve 20 preferably actuated by solenoid 21 which in turn is energized at periodic intervals by means of a conventional automatic timer switch 23 from any suitable source of current (not shown), thus interrupting or restricting the flow of material through outlet 18. Inlet 22 is provided for introducing a stream of the liquid 2,897,972 Patented Aug. 4, 1959 suspension to be treated and is arranged to introduce the stream of liquid suspension tangentially to the wall of chamber 8. V

The apparatus is constructed of any suitable rigid material, preferably steel or stainless steel, the wall of l the conical portion 10 being provided with a threaded portion 24 at its smaller end. A conical outlet member 26 of molded natural or synthetic, elastic, rubber-like material is mounted at the smaller end of conical portion 10, being held in place by compression ring 28 which engages over a laterally outwardly extending flange 30 of elastic member 26 and threadcdly engages threaded portion 24.

Elastic outlet member 26 mates with the smaller end of conical portion 10 to form a continuation thereof and 1; is provided at its vertex with a restricted outlet or exit orifice 32 which is smaller than the opening at the other or inlet end of member 26, the wall of elastic member 26 preferably tapering gradually in thickness toward the vertex where outlet 32 is located and providing with conical portion 10 a smooth continuous inner face extending to the exit orifice 32 as shown in Fig. 3.

The, operation of the device of the present invention to separate solid particles from the liquid suspension is conventional. A stream of liquid suspension influent is introduced through inlet 22 at a relatively high rate of speed in a direction tagential to the wall of chamber 8, causing a vortex to be established with the stream of suspension passing spirally downwardly along the inner Wall of the chamber to a zone close to outlet 32 at the vertex. The central vorteX causes a return stream of the suspension to pass upwardly through the center of the chamber and emerge through outlet 18. By reason of the centrifugal forces set up and slight differences between the specific gravity of the small particles of dirt or. other impurities and the specific gravity of the pulp fibers, the dirt particles tend to separate from the suspension and may be removed through outlet 32 along with a small quantity of the liquid medium. As pointed out above, the diameter of outlet 32 must be relatively small as compared with the diameter of the chamber at its base end and the diameter of main outlet 18 in order to provide effective separation of dirt particles from pulp fiberz In the case of most paper pulp fibers, for example, outlet 32 may have an internal diameter of the order of &is to A inch as compared to a diameter of 3 to 6 inches at the base end of the chamber and a diameter of /2 to 2. inches for outlet 18. Because of the relatively small diameter of outlet 32, it tends to become plugged or obstructed by small particles of dirt, pitch, resin, bundles of wood fibers, etc., which accumulate in the outlet.

In order to clear outlet 32, outlet member 26 may readily be distorted or stretched, for example by simple manual flexing or manipulation of the tip, thus freeing the outlet of the accumulated obstruction.

Inasmuch as separators of this type are frequently employed in batteries Which contain a large'number of individual separators connected to a manifold or header, it

may be inconvenient or impractical to manipulate the tip or vertex of each individual separator manually. Accordingly, valve 20 may be actuated automatically by timer switch 23 and solenoid 21 to close off or restrict temporarily outlet 18 at periodic intervals, thus causing the internal pressure within the chamber and Within outlet 32 to increase rapidly because of the continued introduction of the stream of suspension through inlet 22. This increase in internal pressure above normal operating pressure (which may be approximately atmospheric) causes elastic tip 26 to expand radially, thus enlargin-g outlet 12 and permitting any accumulated foreign particles readily to be expelledtherefrom. It will be understood that when a number-of individual separators are mounted in a battery, all of the outlets 18 may be connected to a manifold or header the outlet to which is controlled by a single valve 20;actuated by-any suitable conventional means, thus clearing a largenumber of'outlets 32 of dirt and tailings simultaneously. The interljup tion or restriction of liquid-suspension' flow through outlet 18 need be only momentary to accomplish-this result.

The precise size and shape of the separatormay be selected in accordance with the nature and cliaracteristics of the particular suspension being treated. lthas been found that in the case of aqueous paper pulp su'spensions, best results are obtained if the length of cylindrical 'chamber 8 is approximately equal to the length of conical portion 10 includingelastic tip 26, the total-length bei-n about 8 to 14 times the maximum diameter. r

suspensions comprising an elongated chamber of circular cross-sectionalconfiguration, means for introducing a stream of the suspension into one end of said chamber tangentially to the wall thereof, a first outlet disposed adjacent said one end, a hollow member formed of rubber-like elastic material secured solely at one end to the other end of said chamber to provide a second outlet for said chamber through the other end of said member, said member being exposedto be freely distorted in any direction to clear said second outlet of accumulated solid material tending to obstruct the same.

2. Apparatus for separating solid particles in liquid F suspensions comprising. an elongated chamber of circular cross-sectional configuration, means for introducing a The length of the radially elastically expansible portion u end ofsaid chamber' to provide' a second outlet for said 26 likewise is not critical provided that theexpansible portion is sutliciently long to permit substantial radial expansion of outlet 32, In the construction described above, for example, in which outlet 32 has an internal diameter of to A inch, expansible tip portion 26may be approximately 2 /2 inches in length. The expansibl'e` tip portion 26 preferably is a one-piece element'molded from a natural or synthetic rubber-like composition. *The exact stittness and rigidity of expansible tip member 26 islikewise not critical and may vary somewhat upon the nature of the liquid suspension being treated. and. the conditions t of operation of the device. The expansibletipshould, of course, be sufiiciently stitf and rigid soasto maintain substantially its original dimensions under. normal op`erating pressure. It should be readily subject to radial: expansion when the internal pressure is increased .as by clos ing valve momentarily and should havesufiicient clasticity so as to return to its original and normal dimensions promptly when the internal pressure-has again'heen re duced to operating pressure.

It will be understood that the device may be operated in any position with outlet 26 directed downwardly, sideways, or vertically upward.

stream of the suspension into one end of said chamber tangentially to the wall thereof, a first outlet disposed adjacent said one end, a hollow member formed of rubberlike elastic material secured solely at one end to the other chamber through the other end ofsaid member, said member being free to expand radially when the pressure within said second outlet is increased above normal operat- I ing pressure to free said second outlet of accumulated solid material tending toobstruct the same.

3. Apparatus for separating solid particles in liquid suspensions comprising an elongated chamber of circular cross-sectional configuration, means forintroducing a stream* of the suspension into one end of said' chamber tangentially to the wall thereof, a first outlet disposed adjacent said one end, a hollow member formed of rubberlike elastic material secured solely at one end to the other end of said chamber to provide a second outlet for said chamber through the other end of said member,

' said member being free to expand* radially when the Although specific embodiments of the invention' have pressure within said second outlet is increased abovenormal operating pressure to free said second outlet of accumulated solid material tending to obstruct the same, and timecontrolled means for intermittently increasing the pressure within said second outlet.

References Cited in the file of this patent- UNITED STATES PATENTS Criner Dec. 23, 1952 ut 4 in -ni Notice of Adverse Becision in Interference In Interference No. `92,389 involving Patent N0. 2,897,972, M. M. *Cannon, SEPARATOR, final judgment adverse to the patentee Was rendered J an. 21, 1'9 64, as to claim 3.

[Ofiicial Gazette Jwne 22, 1965.] 

